The invention relates to a method of automatically servicing winding apparatus in multi-station textile machines and, more particularly, to a method of moving a plurality of doffing carts in a track extending along the front of a textile machine, to be positioned at any one of the winding stations for the purpose of receiving completed or finished bobbins from the winding spindles of the winding station and/or for delivering empty spools to the winding spindles of the winding station.
A winding apparatus servicing method of the described type is known from U.S. Pat. No. 3,895,725. In accordance with the known method a doffing cart is provided which assumes the functions of receiving completed bobbins from all of the winding stations of a multi-station textile machine as well as of delivering empty spools to the winding stations of the machine. In accordance with the method, completed bobbins are transferred directly from the doffing cart to a movable transport frame, the deposit positions of which are arranged in a substantially matching relationship to the winding stations of the textile machine.
If, however, unforeseen yarn breaks occur or if, instead of being changed at predetermined intervals, the bobbins are randomly changed, the demand on the doffing cart may be such that the winding stations may not always be serviced in time. This puts a serious limitation on the efficiency or extent to which the textile machine may be used. Only by having a small number of winding stations associated with each doffing cart may the level of efficiency be raised. However, failures may occur even then. The service time available to the doffing cart is further limited by the fact that the transport frame requires changing whenever it is fully loaded or in case loaded positions have to be serviced again. In any event, mechanically or electrically induced failures of a doffing cart require that the textile machine be either turned off or manually serviced.
The above disadvantage is unavoidable even in the theoretical case in which each winding station of the textile machine is provided with its own doffing cart. The disadvantages are, moreover, compounded by the fact that the known doffing cart assumes the function of yarn handling.
U.S. Pat. No. 4,340,187 discloses a bobbin changing apparatus in which the several operations have been divided. Completed bobbins are transferred to, and removed by, a first bobbin cart, while another doffing cart assumes the function of yarn handling during the exchange of bobbins. Even this system, however, does not permit full, i.e. 100%, utilization of the machine.